socket.c revision 31fdc5553b42abd7e29bb7b89f6ba07514eb4763 
1/*
2 * File: socket.c
3 *
4 * Phonet sockets
5 *
6 * Copyright (C) 2008 Nokia Corporation.
7 *
8 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
9 *          Rémi Denis-Courmont
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * version 2 as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23 * 02110-1301 USA
24 */
25
26#include <linux/gfp.h>
27#include <linux/kernel.h>
28#include <linux/net.h>
29#include <linux/poll.h>
30#include <net/sock.h>
31#include <net/tcp_states.h>
32
33#include <linux/phonet.h>
34#include <linux/export.h>
35#include <net/phonet/phonet.h>
36#include <net/phonet/pep.h>
37#include <net/phonet/pn_dev.h>
38
39static int pn_socket_release(struct socket *sock)
40{
41	struct sock *sk = sock->sk;
42
43	if (sk) {
44		sock->sk = NULL;
45		sk->sk_prot->close(sk, 0);
46	}
47	return 0;
48}
49
50#define PN_HASHSIZE	16
51#define PN_HASHMASK	(PN_HASHSIZE-1)
52
53
54static struct  {
55	struct hlist_head hlist[PN_HASHSIZE];
56	struct mutex lock;
57} pnsocks;
58
59void __init pn_sock_init(void)
60{
61	unsigned int i;
62
63	for (i = 0; i < PN_HASHSIZE; i++)
64		INIT_HLIST_HEAD(pnsocks.hlist + i);
65	mutex_init(&pnsocks.lock);
66}
67
68static struct hlist_head *pn_hash_list(u16 obj)
69{
70	return pnsocks.hlist + (obj & PN_HASHMASK);
71}
72
73/*
74 * Find address based on socket address, match only certain fields.
75 * Also grab sock if it was found. Remember to sock_put it later.
76 */
77struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
78{
79	struct hlist_node *node;
80	struct sock *sknode;
81	struct sock *rval = NULL;
82	u16 obj = pn_sockaddr_get_object(spn);
83	u8 res = spn->spn_resource;
84	struct hlist_head *hlist = pn_hash_list(obj);
85
86	rcu_read_lock();
87	sk_for_each_rcu(sknode, node, hlist) {
88		struct pn_sock *pn = pn_sk(sknode);
89		BUG_ON(!pn->sobject); /* unbound socket */
90
91		if (!net_eq(sock_net(sknode), net))
92			continue;
93		if (pn_port(obj)) {
94			/* Look up socket by port */
95			if (pn_port(pn->sobject) != pn_port(obj))
96				continue;
97		} else {
98			/* If port is zero, look up by resource */
99			if (pn->resource != res)
100				continue;
101		}
102		if (pn_addr(pn->sobject) &&
103		    pn_addr(pn->sobject) != pn_addr(obj))
104			continue;
105
106		rval = sknode;
107		sock_hold(sknode);
108		break;
109	}
110	rcu_read_unlock();
111
112	return rval;
113}
114
115/* Deliver a broadcast packet (only in bottom-half) */
116void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
117{
118	struct hlist_head *hlist = pnsocks.hlist;
119	unsigned int h;
120
121	rcu_read_lock();
122	for (h = 0; h < PN_HASHSIZE; h++) {
123		struct hlist_node *node;
124		struct sock *sknode;
125
126		sk_for_each(sknode, node, hlist) {
127			struct sk_buff *clone;
128
129			if (!net_eq(sock_net(sknode), net))
130				continue;
131			if (!sock_flag(sknode, SOCK_BROADCAST))
132				continue;
133
134			clone = skb_clone(skb, GFP_ATOMIC);
135			if (clone) {
136				sock_hold(sknode);
137				sk_receive_skb(sknode, clone, 0);
138			}
139		}
140		hlist++;
141	}
142	rcu_read_unlock();
143}
144
145void pn_sock_hash(struct sock *sk)
146{
147	struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
148
149	mutex_lock(&pnsocks.lock);
150	sk_add_node_rcu(sk, hlist);
151	mutex_unlock(&pnsocks.lock);
152}
153EXPORT_SYMBOL(pn_sock_hash);
154
155void pn_sock_unhash(struct sock *sk)
156{
157	mutex_lock(&pnsocks.lock);
158	sk_del_node_init_rcu(sk);
159	mutex_unlock(&pnsocks.lock);
160	pn_sock_unbind_all_res(sk);
161	synchronize_rcu();
162}
163EXPORT_SYMBOL(pn_sock_unhash);
164
165static DEFINE_MUTEX(port_mutex);
166
167static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
168{
169	struct sock *sk = sock->sk;
170	struct pn_sock *pn = pn_sk(sk);
171	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
172	int err;
173	u16 handle;
174	u8 saddr;
175
176	if (sk->sk_prot->bind)
177		return sk->sk_prot->bind(sk, addr, len);
178
179	if (len < sizeof(struct sockaddr_pn))
180		return -EINVAL;
181	if (spn->spn_family != AF_PHONET)
182		return -EAFNOSUPPORT;
183
184	handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
185	saddr = pn_addr(handle);
186	if (saddr && phonet_address_lookup(sock_net(sk), saddr))
187		return -EADDRNOTAVAIL;
188
189	lock_sock(sk);
190	if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
191		err = -EINVAL; /* attempt to rebind */
192		goto out;
193	}
194	WARN_ON(sk_hashed(sk));
195	mutex_lock(&port_mutex);
196	err = sk->sk_prot->get_port(sk, pn_port(handle));
197	if (err)
198		goto out_port;
199
200	/* get_port() sets the port, bind() sets the address if applicable */
201	pn->sobject = pn_object(saddr, pn_port(pn->sobject));
202	pn->resource = spn->spn_resource;
203
204	/* Enable RX on the socket */
205	sk->sk_prot->hash(sk);
206out_port:
207	mutex_unlock(&port_mutex);
208out:
209	release_sock(sk);
210	return err;
211}
212
213static int pn_socket_autobind(struct socket *sock)
214{
215	struct sockaddr_pn sa;
216	int err;
217
218	memset(&sa, 0, sizeof(sa));
219	sa.spn_family = AF_PHONET;
220	err = pn_socket_bind(sock, (struct sockaddr *)&sa,
221				sizeof(struct sockaddr_pn));
222	if (err != -EINVAL)
223		return err;
224	BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
225	return 0; /* socket was already bound */
226}
227
228static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
229		int len, int flags)
230{
231	struct sock *sk = sock->sk;
232	struct pn_sock *pn = pn_sk(sk);
233	struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
234	struct task_struct *tsk = current;
235	long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
236	int err;
237
238	if (pn_socket_autobind(sock))
239		return -ENOBUFS;
240	if (len < sizeof(struct sockaddr_pn))
241		return -EINVAL;
242	if (spn->spn_family != AF_PHONET)
243		return -EAFNOSUPPORT;
244
245	lock_sock(sk);
246
247	switch (sock->state) {
248	case SS_UNCONNECTED:
249		if (sk->sk_state != TCP_CLOSE) {
250			err = -EISCONN;
251			goto out;
252		}
253		break;
254	case SS_CONNECTING:
255		err = -EALREADY;
256		goto out;
257	default:
258		err = -EISCONN;
259		goto out;
260	}
261
262	pn->dobject = pn_sockaddr_get_object(spn);
263	pn->resource = pn_sockaddr_get_resource(spn);
264	sock->state = SS_CONNECTING;
265
266	err = sk->sk_prot->connect(sk, addr, len);
267	if (err) {
268		sock->state = SS_UNCONNECTED;
269		pn->dobject = 0;
270		goto out;
271	}
272
273	while (sk->sk_state == TCP_SYN_SENT) {
274		DEFINE_WAIT(wait);
275
276		if (!timeo) {
277			err = -EINPROGRESS;
278			goto out;
279		}
280		if (signal_pending(tsk)) {
281			err = sock_intr_errno(timeo);
282			goto out;
283		}
284
285		prepare_to_wait_exclusive(sk_sleep(sk), &wait,
286						TASK_INTERRUPTIBLE);
287		release_sock(sk);
288		timeo = schedule_timeout(timeo);
289		lock_sock(sk);
290		finish_wait(sk_sleep(sk), &wait);
291	}
292
293	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
294		err = 0;
295	else if (sk->sk_state == TCP_CLOSE_WAIT)
296		err = -ECONNRESET;
297	else
298		err = -ECONNREFUSED;
299	sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
300out:
301	release_sock(sk);
302	return err;
303}
304
305static int pn_socket_accept(struct socket *sock, struct socket *newsock,
306				int flags)
307{
308	struct sock *sk = sock->sk;
309	struct sock *newsk;
310	int err;
311
312	if (unlikely(sk->sk_state != TCP_LISTEN))
313		return -EINVAL;
314
315	newsk = sk->sk_prot->accept(sk, flags, &err);
316	if (!newsk)
317		return err;
318
319	lock_sock(newsk);
320	sock_graft(newsk, newsock);
321	newsock->state = SS_CONNECTED;
322	release_sock(newsk);
323	return 0;
324}
325
326static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
327				int *sockaddr_len, int peer)
328{
329	struct sock *sk = sock->sk;
330	struct pn_sock *pn = pn_sk(sk);
331
332	memset(addr, 0, sizeof(struct sockaddr_pn));
333	addr->sa_family = AF_PHONET;
334	if (!peer) /* Race with bind() here is userland's problem. */
335		pn_sockaddr_set_object((struct sockaddr_pn *)addr,
336					pn->sobject);
337
338	*sockaddr_len = sizeof(struct sockaddr_pn);
339	return 0;
340}
341
342static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
343					poll_table *wait)
344{
345	struct sock *sk = sock->sk;
346	struct pep_sock *pn = pep_sk(sk);
347	unsigned int mask = 0;
348
349	poll_wait(file, sk_sleep(sk), wait);
350
351	if (sk->sk_state == TCP_CLOSE)
352		return POLLERR;
353	if (!skb_queue_empty(&sk->sk_receive_queue))
354		mask |= POLLIN | POLLRDNORM;
355	if (!skb_queue_empty(&pn->ctrlreq_queue))
356		mask |= POLLPRI;
357	if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
358		return POLLHUP;
359
360	if (sk->sk_state == TCP_ESTABLISHED &&
361		atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
362		atomic_read(&pn->tx_credits))
363		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
364
365	return mask;
366}
367
368static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
369				unsigned long arg)
370{
371	struct sock *sk = sock->sk;
372	struct pn_sock *pn = pn_sk(sk);
373
374	if (cmd == SIOCPNGETOBJECT) {
375		struct net_device *dev;
376		u16 handle;
377		u8 saddr;
378
379		if (get_user(handle, (__u16 __user *)arg))
380			return -EFAULT;
381
382		lock_sock(sk);
383		if (sk->sk_bound_dev_if)
384			dev = dev_get_by_index(sock_net(sk),
385						sk->sk_bound_dev_if);
386		else
387			dev = phonet_device_get(sock_net(sk));
388		if (dev && (dev->flags & IFF_UP))
389			saddr = phonet_address_get(dev, pn_addr(handle));
390		else
391			saddr = PN_NO_ADDR;
392		release_sock(sk);
393
394		if (dev)
395			dev_put(dev);
396		if (saddr == PN_NO_ADDR)
397			return -EHOSTUNREACH;
398
399		handle = pn_object(saddr, pn_port(pn->sobject));
400		return put_user(handle, (__u16 __user *)arg);
401	}
402
403	return sk->sk_prot->ioctl(sk, cmd, arg);
404}
405
406static int pn_socket_listen(struct socket *sock, int backlog)
407{
408	struct sock *sk = sock->sk;
409	int err = 0;
410
411	if (pn_socket_autobind(sock))
412		return -ENOBUFS;
413
414	lock_sock(sk);
415	if (sock->state != SS_UNCONNECTED) {
416		err = -EINVAL;
417		goto out;
418	}
419
420	if (sk->sk_state != TCP_LISTEN) {
421		sk->sk_state = TCP_LISTEN;
422		sk->sk_ack_backlog = 0;
423	}
424	sk->sk_max_ack_backlog = backlog;
425out:
426	release_sock(sk);
427	return err;
428}
429
430static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
431				struct msghdr *m, size_t total_len)
432{
433	struct sock *sk = sock->sk;
434
435	if (pn_socket_autobind(sock))
436		return -EAGAIN;
437
438	return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
439}
440
441const struct proto_ops phonet_dgram_ops = {
442	.family		= AF_PHONET,
443	.owner		= THIS_MODULE,
444	.release	= pn_socket_release,
445	.bind		= pn_socket_bind,
446	.connect	= sock_no_connect,
447	.socketpair	= sock_no_socketpair,
448	.accept		= sock_no_accept,
449	.getname	= pn_socket_getname,
450	.poll		= datagram_poll,
451	.ioctl		= pn_socket_ioctl,
452	.listen		= sock_no_listen,
453	.shutdown	= sock_no_shutdown,
454	.setsockopt	= sock_no_setsockopt,
455	.getsockopt	= sock_no_getsockopt,
456#ifdef CONFIG_COMPAT
457	.compat_setsockopt = sock_no_setsockopt,
458	.compat_getsockopt = sock_no_getsockopt,
459#endif
460	.sendmsg	= pn_socket_sendmsg,
461	.recvmsg	= sock_common_recvmsg,
462	.mmap		= sock_no_mmap,
463	.sendpage	= sock_no_sendpage,
464};
465
466const struct proto_ops phonet_stream_ops = {
467	.family		= AF_PHONET,
468	.owner		= THIS_MODULE,
469	.release	= pn_socket_release,
470	.bind		= pn_socket_bind,
471	.connect	= pn_socket_connect,
472	.socketpair	= sock_no_socketpair,
473	.accept		= pn_socket_accept,
474	.getname	= pn_socket_getname,
475	.poll		= pn_socket_poll,
476	.ioctl		= pn_socket_ioctl,
477	.listen		= pn_socket_listen,
478	.shutdown	= sock_no_shutdown,
479	.setsockopt	= sock_common_setsockopt,
480	.getsockopt	= sock_common_getsockopt,
481#ifdef CONFIG_COMPAT
482	.compat_setsockopt = compat_sock_common_setsockopt,
483	.compat_getsockopt = compat_sock_common_getsockopt,
484#endif
485	.sendmsg	= pn_socket_sendmsg,
486	.recvmsg	= sock_common_recvmsg,
487	.mmap		= sock_no_mmap,
488	.sendpage	= sock_no_sendpage,
489};
490EXPORT_SYMBOL(phonet_stream_ops);
491
492/* allocate port for a socket */
493int pn_sock_get_port(struct sock *sk, unsigned short sport)
494{
495	static int port_cur;
496	struct net *net = sock_net(sk);
497	struct pn_sock *pn = pn_sk(sk);
498	struct sockaddr_pn try_sa;
499	struct sock *tmpsk;
500
501	memset(&try_sa, 0, sizeof(struct sockaddr_pn));
502	try_sa.spn_family = AF_PHONET;
503	WARN_ON(!mutex_is_locked(&port_mutex));
504	if (!sport) {
505		/* search free port */
506		int port, pmin, pmax;
507
508		phonet_get_local_port_range(&pmin, &pmax);
509		for (port = pmin; port <= pmax; port++) {
510			port_cur++;
511			if (port_cur < pmin || port_cur > pmax)
512				port_cur = pmin;
513
514			pn_sockaddr_set_port(&try_sa, port_cur);
515			tmpsk = pn_find_sock_by_sa(net, &try_sa);
516			if (tmpsk == NULL) {
517				sport = port_cur;
518				goto found;
519			} else
520				sock_put(tmpsk);
521		}
522	} else {
523		/* try to find specific port */
524		pn_sockaddr_set_port(&try_sa, sport);
525		tmpsk = pn_find_sock_by_sa(net, &try_sa);
526		if (tmpsk == NULL)
527			/* No sock there! We can use that port... */
528			goto found;
529		else
530			sock_put(tmpsk);
531	}
532	/* the port must be in use already */
533	return -EADDRINUSE;
534
535found:
536	pn->sobject = pn_object(pn_addr(pn->sobject), sport);
537	return 0;
538}
539EXPORT_SYMBOL(pn_sock_get_port);
540
541#ifdef CONFIG_PROC_FS
542static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
543{
544	struct net *net = seq_file_net(seq);
545	struct hlist_head *hlist = pnsocks.hlist;
546	struct hlist_node *node;
547	struct sock *sknode;
548	unsigned int h;
549
550	for (h = 0; h < PN_HASHSIZE; h++) {
551		sk_for_each_rcu(sknode, node, hlist) {
552			if (!net_eq(net, sock_net(sknode)))
553				continue;
554			if (!pos)
555				return sknode;
556			pos--;
557		}
558		hlist++;
559	}
560	return NULL;
561}
562
563static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
564{
565	struct net *net = seq_file_net(seq);
566
567	do
568		sk = sk_next(sk);
569	while (sk && !net_eq(net, sock_net(sk)));
570
571	return sk;
572}
573
574static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
575	__acquires(rcu)
576{
577	rcu_read_lock();
578	return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
579}
580
581static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
582{
583	struct sock *sk;
584
585	if (v == SEQ_START_TOKEN)
586		sk = pn_sock_get_idx(seq, 0);
587	else
588		sk = pn_sock_get_next(seq, v);
589	(*pos)++;
590	return sk;
591}
592
593static void pn_sock_seq_stop(struct seq_file *seq, void *v)
594	__releases(rcu)
595{
596	rcu_read_unlock();
597}
598
599static int pn_sock_seq_show(struct seq_file *seq, void *v)
600{
601	int len;
602
603	if (v == SEQ_START_TOKEN)
604		seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
605			"  uid inode ref pointer drops", &len);
606	else {
607		struct sock *sk = v;
608		struct pn_sock *pn = pn_sk(sk);
609
610		seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
611			"%d %pK %d%n",
612			sk->sk_protocol, pn->sobject, pn->dobject,
613			pn->resource, sk->sk_state,
614			sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
615			sock_i_uid(sk), sock_i_ino(sk),
616			atomic_read(&sk->sk_refcnt), sk,
617			atomic_read(&sk->sk_drops), &len);
618	}
619	seq_printf(seq, "%*s\n", 127 - len, "");
620	return 0;
621}
622
623static const struct seq_operations pn_sock_seq_ops = {
624	.start = pn_sock_seq_start,
625	.next = pn_sock_seq_next,
626	.stop = pn_sock_seq_stop,
627	.show = pn_sock_seq_show,
628};
629
630static int pn_sock_open(struct inode *inode, struct file *file)
631{
632	return seq_open_net(inode, file, &pn_sock_seq_ops,
633				sizeof(struct seq_net_private));
634}
635
636const struct file_operations pn_sock_seq_fops = {
637	.owner = THIS_MODULE,
638	.open = pn_sock_open,
639	.read = seq_read,
640	.llseek = seq_lseek,
641	.release = seq_release_net,
642};
643#endif
644
645static struct  {
646	struct sock *sk[256];
647} pnres;
648
649/*
650 * Find and hold socket based on resource.
651 */
652struct sock *pn_find_sock_by_res(struct net *net, u8 res)
653{
654	struct sock *sk;
655
656	if (!net_eq(net, &init_net))
657		return NULL;
658
659	rcu_read_lock();
660	sk = rcu_dereference(pnres.sk[res]);
661	if (sk)
662		sock_hold(sk);
663	rcu_read_unlock();
664	return sk;
665}
666
667static DEFINE_MUTEX(resource_mutex);
668
669int pn_sock_bind_res(struct sock *sk, u8 res)
670{
671	int ret = -EADDRINUSE;
672
673	if (!net_eq(sock_net(sk), &init_net))
674		return -ENOIOCTLCMD;
675	if (!capable(CAP_SYS_ADMIN))
676		return -EPERM;
677	if (pn_socket_autobind(sk->sk_socket))
678		return -EAGAIN;
679
680	mutex_lock(&resource_mutex);
681	if (pnres.sk[res] == NULL) {
682		sock_hold(sk);
683		rcu_assign_pointer(pnres.sk[res], sk);
684		ret = 0;
685	}
686	mutex_unlock(&resource_mutex);
687	return ret;
688}
689
690int pn_sock_unbind_res(struct sock *sk, u8 res)
691{
692	int ret = -ENOENT;
693
694	if (!capable(CAP_SYS_ADMIN))
695		return -EPERM;
696
697	mutex_lock(&resource_mutex);
698	if (pnres.sk[res] == sk) {
699		RCU_INIT_POINTER(pnres.sk[res], NULL);
700		ret = 0;
701	}
702	mutex_unlock(&resource_mutex);
703
704	if (ret == 0) {
705		synchronize_rcu();
706		sock_put(sk);
707	}
708	return ret;
709}
710
711void pn_sock_unbind_all_res(struct sock *sk)
712{
713	unsigned int res, match = 0;
714
715	mutex_lock(&resource_mutex);
716	for (res = 0; res < 256; res++) {
717		if (pnres.sk[res] == sk) {
718			RCU_INIT_POINTER(pnres.sk[res], NULL);
719			match++;
720		}
721	}
722	mutex_unlock(&resource_mutex);
723
724	while (match > 0) {
725		__sock_put(sk);
726		match--;
727	}
728	/* Caller is responsible for RCU sync before final sock_put() */
729}
730
731#ifdef CONFIG_PROC_FS
732static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
733{
734	struct net *net = seq_file_net(seq);
735	unsigned int i;
736
737	if (!net_eq(net, &init_net))
738		return NULL;
739
740	for (i = 0; i < 256; i++) {
741		if (pnres.sk[i] == NULL)
742			continue;
743		if (!pos)
744			return pnres.sk + i;
745		pos--;
746	}
747	return NULL;
748}
749
750static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
751{
752	struct net *net = seq_file_net(seq);
753	unsigned int i;
754
755	BUG_ON(!net_eq(net, &init_net));
756
757	for (i = (sk - pnres.sk) + 1; i < 256; i++)
758		if (pnres.sk[i])
759			return pnres.sk + i;
760	return NULL;
761}
762
763static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
764	__acquires(resource_mutex)
765{
766	mutex_lock(&resource_mutex);
767	return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
768}
769
770static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
771{
772	struct sock **sk;
773
774	if (v == SEQ_START_TOKEN)
775		sk = pn_res_get_idx(seq, 0);
776	else
777		sk = pn_res_get_next(seq, v);
778	(*pos)++;
779	return sk;
780}
781
782static void pn_res_seq_stop(struct seq_file *seq, void *v)
783	__releases(resource_mutex)
784{
785	mutex_unlock(&resource_mutex);
786}
787
788static int pn_res_seq_show(struct seq_file *seq, void *v)
789{
790	int len;
791
792	if (v == SEQ_START_TOKEN)
793		seq_printf(seq, "%s%n", "rs   uid inode", &len);
794	else {
795		struct sock **psk = v;
796		struct sock *sk = *psk;
797
798		seq_printf(seq, "%02X %5d %lu%n",
799			   (int) (psk - pnres.sk), sock_i_uid(sk),
800			   sock_i_ino(sk), &len);
801	}
802	seq_printf(seq, "%*s\n", 63 - len, "");
803	return 0;
804}
805
806static const struct seq_operations pn_res_seq_ops = {
807	.start = pn_res_seq_start,
808	.next = pn_res_seq_next,
809	.stop = pn_res_seq_stop,
810	.show = pn_res_seq_show,
811};
812
813static int pn_res_open(struct inode *inode, struct file *file)
814{
815	return seq_open_net(inode, file, &pn_res_seq_ops,
816				sizeof(struct seq_net_private));
817}
818
819const struct file_operations pn_res_seq_fops = {
820	.owner = THIS_MODULE,
821	.open = pn_res_open,
822	.read = seq_read,
823	.llseek = seq_lseek,
824	.release = seq_release_net,
825};
826#endif
827